Short interconnect assembly with strip elastomer

ABSTRACT

An electrical contact assembly that uses an elastomer strip for each row of individual contacts. Each contact comprises a rigid bottom pin and a flexible top pin with a pair of arms which extend over and slide along sloped concave surfaces of the bottom contact. The elastomer strip is located between rows of the bottom and top pins. A bottom socket housing is provided with grooves which receive each elastomer strip. A row of top pins is then placed over each elastomer strip, and through ducts in the bottom socket housing. Bottom pins are then snapped into place in between the pair of arms.

FIELD OF INVENTION

The present invention relates generally to an integrated circuit (IC)testing apparatus, and more specifically to an integrated circuit (IC)testing apparatus with elastomer strips.

BACKGROUND OF INVENTION

An integrated circuit (IC) device testing apparatus is used to evaluateperformance of the IC device, and to remove from further productionthose IC devices that are faulty. Many solutions exist for effectiveelectrical connection between the leads of the IC device and that of thetesting apparatus, and they are known as interconnect assemblies. Onetype of interconnect assembly is a matrix type which is used to testball grid array (BGA) devices, and it allows for the testing of ICdevices that have leads over any portion of its entire surface.Interconnect assemblies of this matrix type must have electrical contactpins arranged in a matrix, as opposed to only at the outer edges of theIC device. It is preferable that the electrical contact pins can beeasily customized so that multiple configurations of IC devices can betested.

U.S. Pat. No. 9,817,026 (Edwards, et al) teaches of such an interconnectassembly, employing a matrix of electrical contact pins for electricalconnection between the IC device being tested and the testing apparatus.One problem with interconnect assemblies such as that taught by Edwardset al is that the upper pin 22 and lower pin 62 are only held in contactwith each other by the constrictive force from the surrounding honeycombshaped elastomer 80. This design requires pressing of the elastomeragainst all sides of the moving pins, which generates friction betweenthe elastomer and pins during testing. This friction can cause the upperpin to become stuck and thus delay its upwards retraction as the ICdevice and testing apparatus are separated from each other. As there aretens of thousands of test cycles an hour, any delay in the movement ofthe pins is not desirable.

Furthermore, the rubber honeycomb loses elasticity over time, and thiscauses a reduction in clamping force on the pins, thus reducing thequality of contact between the upper and lower pins. This increases thechances of a contact failure.

Yet another problem with this design is the inability to maintain thetemperature of the testing environment. One type of test carried out onIC devices is called tri-temperature testing. This is when the testingenvironment is set at three different temperatures, roughly −40° C.,ambient, and 150° C. To maintain the testing environment at thistemperature, air is heated or cooled to the desired testing temperatureand circulated around the testing environment. Air flow around theinterconnect assembly causes it to reach the desired testingtemperature. In Edward et al's design, the sheer volume and shape takenby the elastomer restricts air circulation around the interconnectassembly, thus making it difficult to maintain the interconnect assemblyat the desired temperature.

Another problem with interconnect assemblies employing the sheet typeelastomers such as taught by Edwards et al is that any warping of theelastomer sheet can lead to different elastomer compression across thematrix, thus causing coplanarity issues. BGA devices require coplanarityto best control and absorb ball height variations. Another drawback withsheet elastomers is the need to handle the entire elastomer sheet duringinstallation or rebuilding of the interconnect assembly. To make mattersworse, the elastomer sheet is also prone to tearing during theseinstallation and rebuilding processes. Cutting of the elastomer sheetsto the specific pitching and size for the pin slots is a complex processthat results in many rejected elastomer sheets.

Sheet type elastomer designs such as that taught in Edwards et al alsosuffer from high frequency signal losses during testing.

What is needed in the art is an interconnect assembly that eliminates orreduces the afore-mentioned disadvantages of friction between theelastomer and pins, loss in electrical contact quality over time and thedifficulty in maintaining interconnect assembly temperature duringtri-temperature testing.

SUMMARY OF INVENTION

The present invention seeks to overcome the aforementioned disadvantagesby providing an electrical interconnect assembly that uses an elastomerstrip for each row of individual contacts. Each contact comprises arigid bottom pin and a flexible top pin with a pair of arms which extendover and slide along sloped concave surfaces of the bottom contact. Theelastomer strip is located between rows of the bottom and top pins. Abottom socket housing is provided with grooves which receive eachelastomer strip. A row of top pins is then placed over each elastomerstrip, and through ducts in the bottom socket housing. Bottom pins arethen snapped into place in between the pair of arms.

This invention thus relates to an electrical interconnect assembly foruse in an integrated circuit (IC) device testing apparatus, comprising:a bottom socket housing having a plurality of grooves running parallelwith respect to each other, said grooves located on an upper side ofsaid bottom socket housing, and a plurality of ducts which piercethrough from said upper side to a lower side of said bottom sockethousing, said plurality of ducts spaced along each said groove; aplurality of bottom rows, each said bottom row comprising a plurality ofrigid bottom pins, each said bottom pin having two concave surfacessloping towards each other, each said bottom pin having an upper end,each said bottom pin adapted to be inserted through each said duct, andeach said bottom pin formed of an electrically conductive material; aplurality of top rows, each said top row comprising a plurality offlexible top pins, each said top pin having a contact head at its topend, a horizontal member having two ends and joined at its center to abottom part of said contact head, a first and a second arm joined to andextending downwards from each horizontal member end, said arms having aninwards bias such that an inner surface of each said arm is pressed incontact with each said concave surface, said top pin formed of anelectrically conductive material, and each said top row aligned witheach said bottom row; and a plurality of elastomer strips, each saidelastomer strip running along the length of each said bottom row and toprow, cross sections of each elastomer strip enclosed within said upperends of said plurality of bottom pins in each bottom row, and saidhorizontal members and said arms in each top row, wherein during a testof an IC device, the device is lowered onto said top pin, therebypushing it down and compressing at least a portion of said elastomerstrip while simultaneously spreading said arms as they slide down thesaid sloping concave surfaces. The horizontal member has a downwardsfacing surface that is flat along a substantial portion of it.

This invention also relates to the electrical interconnect assembly foruse in an integrated circuit testing apparatus above, wherein said toppin having a contact head which contacts with an IC device, said contacthead being narrower than said horizontal member.

This invention also relates to the electrical interconnect assembly foruse in an integrated circuit testing apparatus above, further comprisinga top socket housing having a plurality of grooves running parallel withrespect to each other, said grooves located on a lower side of said topsocket housing, and a plurality of ducts which pierce through from saidlower side to an upper side of said top socket housing, said pluralityof ducts spaced along each said groove, each said groove adapted toreceive each said top row.

This invention also relates to the electrical interconnect assembly foruse in an integrated circuit testing apparatus above, wherein each saidduct is adapted to have said contact head inserted through it.

This invention also relates to the electrical interconnect assembly foruse in an integrated circuit testing apparatus above, wherein each saidduct is large enough to have said contact head inserted through, but notlarge enough for the said horizontal member to go through.

This invention also relates to the electrical interconnect assembly foruse in an integrated circuit testing apparatus above, wherein the innersurfaces of the top pin arms are provided with curved bulges where theycontact with said concave surfaces of the bottom pin.

This invention also relates to the electrical interconnect assembly foruse in an integrated circuit testing apparatus above, wherein the upperend of the bottom pin has an upwards facing surface that is concave.

Other embodiments of this invention are possible with variations to thecross-sectional shape of the elastomer strip. The possible shapes of theelastomer strip can be, but are not limited to, any of the following:square, oblong, hexagon, and octagonal. In each case, the length of thetop pin horizontal member may be adapted to match and receive the saidelastomer strip. The upper end of the bottom pin may also be adapted tomatch and receive the bottom of the elastomer strip.

The present invention comprises five main structural elements with adesign that allows for quick assembly, and allows control of gram forceby virtue of the placement of the compressible member in its design. Thebottom pin and top pin comprise the electrical contacting components,while the elastomer strip acts as the spring force acting against acompressive force of the bottom and top pins. The bottom socket housingcomprises grooves which hold each elastomer strip in place, and ductsthat allow the bottom pin and top pin arms to be inserted through. Onceeach elastomer strip is secured in a bottom socket housing groove, aplurality of top pins is slid in a spaced fashion along the length ofthe elastomer strip, and due to the snug fit of the elastomer strip topportion within the top pin, each top pin is held in place until a row isassembled, which we call the top row. Bottom pins are then snapped intoplace in between the flexible arms of the top pin, and are also held inplace within the top pin arms and elastomer strip. The top sockethousing is provided with ducts that allow the contact head of the toppin to slide through during assembly and testing. In this way, eachinterconnect assembly is held securely in place via an easy assemblyprocess.

Due to the design of the interconnect assembly in the present invention,the elastomer does not wrap around the pins as in Edwards et al, andthus friction between the elastomer and pins is not only significantlyless, but also does not cause any restriction in the upwards retreat ofthe top pin when the IC device is separated from the testing apparatusduring the latter part of each test cycle. The problem of delay inmovement of the top pin is thus solved in the present invention, and ahigh testing rate can be achieved.

The problem of a reduction in elasticity of the elastomer causing areduction in quality of electrical contact between the pins is alsosolved in the present invention, as the contact force between the pinsis not provided by the elastomer as in Edwards et al, but in fact by theclamping force of the top pin's arms against the bottom pin.

The problem of maintaining a temperature of the interconnect assemblyduring tri-temperature testing is also solved in the present invention,due to the much smaller volume of the elastomer compared to that ofEdwards et al. There is thus more empty space around the pins, allowingfor better air circulation and temperature conditioning of theinterconnect assembly by the surrounding air.

The present invention allows a user to customize the configuration ofpins on-site, as required by the particular test. While prior artmethods require the entire board to be delivered pre-configured by themanufacturer, the present invention allows easy removal of the bottomand top pins by the user, on-site, so that the contact pins may be addedor removed as needed to form any configuration that is required in amatrix. This is important for ball grid array IC device testing.

The singulated or strip elastomers of the present invention also allowsquick and easy installation and rebuilding of the interconnect assembly,as well as replacement of faulty electrical contact pins by the user,on-site. This is in addition to the ease of removability of the bottomand top pins.

The present invention can operate under higher testing temperatures, byvirtue of its design. Many prior art designs, such as the spring andpogo pin design, are susceptible to deformation at high temperatures.This does not happen with the contact pin design of the presentinvention.

The problem of warping of the elastomer sheet is also reduced in thepresent invention, thus improving coplanarity issues that is importantfor testing BGA devices.

The strip elastomer in the present invention also reduces high frequencysignal losses compared to the sheet type elastomers. Signal integrity isa factor of the contact material, length and structural stability. Theelectrical contacts of this invention provide a much stronger electricalconnection between each top and bottom pin, which translates to bettersignal integrity and lower signal losses. The contact design in Edwardshas only one mating surface for each pin, compared the two in thepresent invention. Each contact pin also connects diagonally with eachother, which creates horizontal forces during a test that tends to pushthe contacts away from each other, thus resulting in less signalintegrity. In contrast, the design of the present invention creates astronger electrical connection between the top and bottom pins as thetop pin is lowered towards the bottom pin, due to the clamp design ofthe top pin. In short, designs such as Edwards have higher signal lossescompared to the design of the present invention.

Other objects and advantages will be more fully apparent from thefollowing disclosure and appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a cross-sectional view of an electrical contact assembly inan embodiment of the present invention.

FIG. 2 shows a perspective view of an assembled bottom pin, top pin andD-shaped elastomer strip in an embodiment of the present invention.

FIG. 3 shows a front view of a bottom pin and top pin in an embodimentof the present invention.

FIG. 4 shows a perspective view of a D-shaped elastomer strip in anembodiment of the present invention.

FIG. 5 shows a perspective view of a bottom socket housing in anembodiment of the present invention.

FIG. 6 shows a bottom perspective view of a top socket housing in anembodiment of the present invention.

FIG. 7 shows a perspective view of an elastomer strip assembled onto abottom socket housing in an embodiment of the present invention.

FIG. 8 shows a cross-sectional perspective view of an elastomer stripassembled onto a bottom socket housing in an embodiment of the presentinvention.

FIG. 9 shows a perspective view of a top pin being assembled onto anelastomer strip in an embodiment of the present invention.

FIG. 10 shows a perspective view of a top pin assembled onto anelastomer strip in an embodiment of the present invention.

FIG. 11 shows a cross-sectional perspective view of a top pin assembledonto an elastomer strip in an embodiment of the present invention.

FIG. 12 shows a cross-sectional perspective view of a bottom pin beingassembled into a top pin in an embodiment of the present invention.

FIG. 13 shows a cross-sectional perspective view of all bottom pinsassembled into all top pins in an embodiment of the present invention.

FIG. 14 shows a perspective view of a tapered elastomer strip in anembodiment of the present invention.

FIG. 15 shows a perspective view of an assembled bottom pin, top pin andtapered elastomer strip in an embodiment of the present invention.

FIG. 16 shows a perspective view of a rectangular elastomer strip in anembodiment of the present invention.

FIG. 17 shows a perspective view of an assembled bottom pin, top pin andrectangular elastomer strip in an embodiment of the present invention.

FIG. 18 shows a perspective view of an oval elastomer strip in anembodiment of the present invention.

FIG. 19 shows a perspective view of an assembled bottom pin, top pin andoval elastomer strip in an embodiment of the present invention.

REFERENCE SIGNS

-   Bottom pin (10)-   Left concave surface (12) of bottom pin-   Right concave surface (14) of bottom pin-   Upper end (16) of bottom pin-   Head (18) of bottom pin-   Top pin (20)-   Left arm (22) of top pin-   Left arm inner surface (221) of top pin-   Horizontal member (23)-   Horizontal member left end (231)-   Horizontal member right end (232)-   Right arm (24) of top pin-   Right arm inner surface (241) of top pin-   Top pin contact head (28)-   Elastomer strip (30)-   Elastomer strip top portion (32)-   Bottom socket housing (40)-   Grooves (42) of bottom socket housing-   Ducts (44) of bottom socket housing-   Upper side (46) of bottom socket housing-   Lower side (48) of bottom socket housing-   Top socket housing (50)-   Grooves (52) of top socket housing-   Ducts (54) of top socket housing-   Lower side (56) of top socket housing-   Upper side (58) of top socket housing

DETAILED DESCRIPTION OF INVENTION

It should be noted that the following detailed description is directedto an electrical contact of an integrated circuit testing apparatus, andis not limited to any particular size or configuration but in fact amultitude of sizes and configurations within the general scope of thefollowing description.

FIG. 1 shows a cross-sectional view of a fully assembled electricalcontact of an integrated circuit (IC) testing apparatus in an embodimentof this invention. FIG. 2 shows a close-up perspective view of anassembled bottom pin (10), top pin (20) and D-shaped elastomer strip(30) without the bottom socket housing (40) and top socket housing (50),to provide a clearer illustration of these elements. FIG. 3 shows thebottom pin (10) and top pin (20) without the elastomer. FIG. 4 showsonly the elastomer (30).

Referring to FIGS. 1 through 4 , there is shown a plurality of rigidbottom pins (10) arranged in rows, each said bottom pin having a leftconcave surface (12) and a right concave surface (14) that slope towardseach other, so that said bottom pin forms a partial wedge shape, with anarrower upper end (16) of the wedge facing upwards. Each said bottompin (10) is in electrical connection with a corresponding top pin (20),said top pin having a contact head (28) at its top end, a horizontalmember (23) having two ends (231, 232) and joined at its center to abottom part of said contact head. The horizontal member (23) has adownwards facing surface that is flat along a substantial portion of it.Each top pin also has a first (22) and a second (24) arm joined to andextending downwards from each horizontal member end (231, 232), saidarms (22, 24) having an inwards bias such that an inner surface (221,241) of each said arm is pressed in contact with each said bottom pinconcave surface (12, 14). The inner surfaces (221, 241) are providedwith curved bulges where they contact with the concave surfaces (12, 14)of the bottom pin (10).

The top pin (20) is designed to allow flexing of the two arms (22, 24),that is, the arms (22, 24) are able to spread open from each otheraround the two horizontal member ends (231, 232), to an extent. The saidarms (22, 24) are designed to have an inwards bias such that an innersurface (221) of said left arm (22) is pressed in contact with said leftconcave surface (12), and an inner surface (241) of said right arm (24)is pressed in contact with said right concave surface (14). In this way,during an IC device test and as the top pin (20) moves vertically withrespect to the bottom pin (10), the bottom pin (10) and top pin (20)maintain a strong electrical connection with each other. The bottom pin(10) and top pin (20) can be made from any electrically conductivematerial with the appropriate properties that allow the bottom pin (10)to be substantially rigid, and the top pin arms (22, 24) to flex to adesired amount. The top pin (20) has a contact head (28) which isnarrower than the width of the horizontal member (23). The contact head(28) provides electrical contact with leads on the IC device duringtesting.

Also shown in FIG. 1 is a plurality of elastomer strips (30). Eachelastomer strip (30) is located between a row of bottom pins (10) and arow of top pins (20). Generally, each said elastomer strip (30) hascross-sections that are enclosed within said upper ends (16) of saidplurality of bottom pins (10) in each bottom row, and said horizontalmembers (23) and said arms (22, 24) in each top row. The upper end (16)of the bottom pin (10) has an upwards facing surface that is concave,which allows for better grip between the bottom pin (10) and theelastomer (30).

FIG. 2 shows a clearer view of just one elastomer strip (30) with onebottom pin (10) and one corresponding top pin (20). Each said elastomerstrip (30) is elongated along a horizontal plane, which plane isperpendicular to a vertical movement of the top pin (20) during an ICdevice test, and hence a direction of a compressive force applied duringtesting. Each elastomer strip (30) is designed to act as a compressiblemember, such that a compression force acting on the bottom pin (10) andtop pin (20) (as happens during testing of an IC device) will cause theelastomer strip (30) to compress and thus provide an opposing force tothe said compression. Simultaneously, the arms (22, 24) of the top pin(20) are forced to spread apart as their inner surfaces (221, 241) slidedown over the corresponding sloped concave surfaces (12, 14) of thebottom pin (10). When the compressive force is released, the elastomerstrip (30), acting like a spring, expands thus pushing the bottom pins(10) and top pins (20) vertically away from each other, but still inelectrical contact with each other due to the inward bias of the arms(22, 24) clamping against the concave surfaces (12, 14).

FIG. 3 shows a clearer view of the bottom (10) and top (20) pins. Thetop pin (20) having a contact head (28) at its upper end, which isjoined to a center of a horizontal member (23). The horizontal member(23) extends horizontally on each side of the contact head (28) to twoends (231, 232). Two arms (22, 24) extend downwards, one from each saidend (231, 232). The lower end of each arm (22, 24) is provided with acurved bulge at their inner surfaces (221, 241). These inner surfaces(221, 241) are in electrical contact with concave surfaces (12, 14) ofthe bottom pin (10). The bottom pin (10) is also provided with a head(18) at its upper end, which head is wider than the narrowest section ofthe bottom pin (10).

Referring to FIGS. 1 through 4 , during testing of an IC device, the toppin (20) is first subjected to a downwards force from an IC device (notshown) from above. When this happens, the elastomer strip (30)compresses and allows the said top pin (20) to move closer towards thebottom pin (10). As this happens, the inner surfaces (221, 241) of thesaid arms (22, 24) slide downwards along the sloping concave surfaces(12, 14) of the bottom pin (10), and the two arms (22, 24) of the toppin (20) flex outwards, and maintain inward pressure on the said concavesurfaces (12, 14) of said bottom pin (10). When the IC device is liftedaway from the testing apparatus, the elastomer strip (30) decompressesand forces the top pin (20) away from the said bottom pin (10). As thishappens, the inwards bias of the two arms (22, 24) acting on the saidconcave surfaces (12, 14) of bottom pin (10) keeps the inner surfaces(221, 241) of each arm in contact with the said concave surfaces (12,14) of the said bottom pin (10). In this way, strong electrical contactis maintained throughout the testing period.

The horizontal member (23) and downward extending arms (22, 24) are newelements that provide improvements on U.S. patent application Ser. No.17/344,499, which is hereby incorporated by reference in its entirety.These elements cause the top pin to be more rectangular shaped. Arectangular shaped top pin allows better retraction of the top pin (itsupwards movement with respect to the bottom pin), as there is lessexpansion of the arms (22, 24) during a test. Less expansion of the arms(22, 24) during a test reduces stiffness of the arms and friction at thecontact area between the top pin (20) and bottom pin (10). Thehorizontal member (23) also provides a flatter contact area between thetop pin (20) and the elastomer (30). This minimizes tearing of theelastomer (30).

The concave surfaces (12, 14) of the bottom pin and the curved bulges oneach arm inner surface (221, 241) are also new elements that provideimprovements on the U.S. patent application Ser. No. 17/344,499.Concavity of the surfaces (12, 14) together with the curved bulges oneach arm inner surface (221, 241) further enhances retraction of the toppin (20), as the concave surfaces add to the force provided by theelastomer during retraction of the top pin (20). This reduces thereliance of the top pin retraction on the elastomer alone.

The concave bottom pin upper end (16) is yet another new element thatprovides improvements on U.S. patent application Ser. No. 17/344,499.Concavity of this upper end allows better grip between the bottom pin(10) and the elastomer (30).

The elastomer strip (30) may be formed in a multitude of cross-sectionalshapes. In a first embodiment, shown in FIG. 3 , the elastomer strip(30) has a D-shaped cross-section. The curve of the “D” is facingupwards, making the top (32) of the elastomer strip (30) curved.

FIG. 5 shows a bottom socket housing (40) in an embodiment of thisinvention. Referring to FIGS. 1 and 5 now, the bottom socket housing(40) is provided with a plurality of grooves (42) that are parallel witheach other and each groove (42) forming an elongated cavity along anupper side (46) of said bottom socket housing (40). The bottom sockethousing (40) is also provided with a plurality of ducts (44) thatvertically pierce through the bottom socket housing (40) from an upperside (46) to a lower side (48) of said bottom socket housing (40). Theducts (44) are spaced along said grooves (42). Each said elastomer strip(30) sits within said groove (42), and each pair of arms (22, 24)partially extends down through each said duct (44). Each bottom pin (10)extends upwards into each said duct (44).

FIG. 6 shows a top socket housing (50) in an embodiment of thisinvention. Referring to FIGS. 1 and 5 now, the top socket housing (50)is provided with a plurality of grooves (52) that are parallel with eachother and each groove (52) forming an elongated cavity along a lowerside (56) of said top socket housing (50). The top socket housing (50)is also provided with a plurality of ducts (54) that vertically piercethrough the top socket housing (50) from an upper side (58) to a lowerside (56) of said top socket housing (50). The ducts (54) are spacedalong said grooves (52). The ducts (54) of the top socket housing (50)have a size that allows said contact head (28) of the top pin (20), butnot the said horizontal member (23) to pass through.

FIGS. 7 through 13 show a sequence of a method of assembling theelectrical contact in an embodiment of the present invention.

FIG. 7 shows a D-shaped elastomer strip (30) as it is being lowered intoa groove (42) of a bottom socket housing (40). FIG. 8 shows across-sectional perspective view of the elastomer strip (30) assembledinto the groove (42) of the bottom socket housing (40). There is alsoshown the ducts (44) of the bottom socket housing (40) in this figure.FIG. 9 shows a top pin (20) being lowered onto the elastomer strip (30)which has been installed on the bottom socket housing (40). FIGS. 10 and11 shows the top pin (20) assembled onto an elastomer strip (30).

FIG. 12 shows a bottom pin (10) being raised up through a duct (44) ofthe bottom socket housing (40). The bottom pin (10) has a head (18) thatis slightly wider than the narrowest part of its tapered section. Thewidth of this head (18) is such that it allows the bottom pin (10) tosnap into the arms (22, 24) of the top pin (20) and remain securedthere.

It is also clear from FIG. 12 that the ducts (shown in FIG. 6 as 54) inthe top socket housing (50) allow only the contact head (28) of the toppin (20) to pass through, and does not allow the horizontal member (23)to pass through it. In this way, the top socket housing (50) preventsthe top pin (20) from upwards movement relative to the top sockethousing (50). The top socket housing (50) and bottom socket housing (40)thus secure the electrical contact assembly in place.

FIG. 13 shows all bottom pins (10) assembled into all top pins (20). Itcan be seen from this figure how the main elements of this assembly keepthe assembly secured in place. In essence, the elastomer strip (30) isheld up by the bottom socket housing (40). The elastomer strip (30) inturn holds up the top pins (20). The bottom pin (10) is held in place bythe upwards pull of the arms (22, 24) acting on its head (18) and thedownwards force of the bottom of the elastomer strip (30). Lastly, thetop socket housing (50) keeps each contact from moving upwards.

FIG. 14 shows an embodiment where the elastomer strip (30) has a taperedor hexagonal cross-section.

FIG. 15 shows the tapered or hexagonal cross-sectioned elastomer stripassembled with the bottom pin (10) and top pin (20).

FIG. 16 shows an embodiment where the elastomer strip (30) has arectangular cross-section.

FIG. 17 shows the rectangular cross-sectioned elastomer strip assembledwith the bottom pin (10) and top pin (20).

FIG. 18 shows an embodiment where the elastomer strip (30) has an ovalcross-section.

FIG. 19 shows the oval cross-sectioned elastomer strip assembled withthe bottom pin (10) and top pin (20).

While several particularly preferred embodiments of the presentinvention have been described and illustrated, it should now be apparentto those skilled in the art that various changes and modifications canbe made without departing from the scope of the invention. Accordingly,the following claims are intended to embrace such changes,modifications, and areas of application that are within the scope ofthis invention.

The invention claimed is:
 1. An electrical contact for use in anintegrated circuit (IC) device testing apparatus, comprising: a bottomsocket housing having a plurality of grooves running parallel withrespect to each other, said grooves located on an upper side of saidbottom socket housing, and a plurality of ducts which pierce throughfrom said upper side to a lower side of said bottom socket housing, saidplurality of ducts spaced along each said groove; a plurality of bottomrows, each said bottom row comprising a plurality of rigid bottom pins,each said bottom pin having two concave surfaces sloping towards eachother, each said bottom pin having an upper end, each said bottom pinadapted to be inserted through each said duct, and each said bottom pinformed of an electrically conductive material; a plurality of top rows,each said top row comprising a plurality of flexible top pins, each saidtop pin having a contact head at its top end, a horizontal member havingtwo ends and joined at its center to a bottom part of said contact head,a first and a second arm joined to and extending downwards from eachhorizontal member end, said arms having an inwards bias such that aninner surface of each said arm is pressed in contact with each saidconcave surface, said top pin formed of an electrically conductivematerial, and each said top row aligned with each said bottom row; and aplurality of elastomer strips, each said elastomer strip running alongthe length of each said bottom row and top row, cross sections of eachelastomer strip enclosed within said upper ends of said plurality ofbottom pins in each bottom row, and said horizontal members and saidarms in each top row wherein during a test of an IC device, the deviceis lowered onto said top pin, thereby pushing it down and compressing atleast a portion of said elastomer strip while simultaneously spreadingsaid arms as they slide down the said sloping concave surfaces.
 2. Anelectrical contact for use in an integrated circuit testing apparatusaccording to claim 1, wherein said top pin having a contact head whichcontacts with an IC device, said contact head being narrower than saidhorizontal member.
 3. An electrical contact for use in an integratedcircuit testing apparatus according to claim 2, further comprising a topsocket housing having a plurality of grooves running parallel withrespect to each other, said grooves located on a lower side of said topsocket housing, and a plurality of ducts which pierce through from saidlower side to an upper side of said top socket housing, said pluralityof ducts spaced along each said groove, each said groove adapted toreceive each said top row.
 4. An electrical contact for use in anintegrated circuit testing apparatus according to claim 3, wherein eachsaid duct is adapted to have said contact head inserted through it. 5.An electrical contact for use in an integrated circuit testing apparatusaccording to claim 3, wherein each said duct is large enough to havesaid contact head inserted through, but not large enough for saidhorizontal member to go through.
 6. An electrical contact for use in anintegrated circuit testing apparatus according to claim 1, wherein saidinner surfaces are provided with curved bulges where they contact withsaid concave surfaces.
 7. An electrical contact for use in an integratedcircuit testing apparatus according to claim 1, wherein said upper endhas an upwards facing surface that is concave.
 8. An electrical contactfor use in an integrated circuit testing apparatus according to claim 1,wherein said horizontal member has a downwards facing surface that isflat along a substantial portion of it.